Research Infrastructures are resources enabling excellent scientific research. The growing demand for large, complex and expensive research infrastructures by the research community and at the same time an increasing demand by politics regarding a close scrutiny of research funding challenges policy- and decision-makers. A decision-making process in view of prioritizing and funding large-scale research infrastructures is complex due to the multiple number of actors and levels involved. Formalized decision-making processes in the shape of roadmap exercises for research infrastructure were introduced in the Science, Technology and Innovation (STI) governance of many countries. The main intention was to overcome coordination failures of relevant actors and to achieve a strategic plan for scientists and policy makers. Within an ideal "roadmap process" the science communities reflect strategically about their own research priorities. At the same time policy-makers integrate their strategic and political priorities into the process (OECD 2008). Yet, there is no academic research available on the functioning of these processes. The overall objective of the research project is to understand the national decision-making processes for prioritizing and funding of large-scale research infrastructures at national level, and the rationales behind the design of the formalized roadmap process.